nd.take with ?bool

[mrocklin]

I actually don't know what proper behavior is here. Maybe return an option type with the missing values? It might be worth looking into how systems like R do this.

In [1]: from dynd import nd

In [2]: x = nd.array([1, 10, None], dtype='?int')

In [3]: nd.take(x, x > 5)
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-3-97c4aec2b521> in <module>()
----> 1 nd.take(x, x > 5)

dynd/nd/callable.pyx in dynd.nd.callable.callable.__call__ (/home/travis/build/libdynd/dynd-python/build/temp.linux-x86_64-3.4/callable.cxx:786)()

ValueError: take: unsupported type for the index ?bool, need bool or intptr

[mwiebe]

I guess do what R does. See http://docs.scipy.org/doc/numpy/neps/missing-data.html#boolean-indexing for some previous thoughts on it.